#region Copyright notice and license

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#endregion

using System;
using System.Collections.Generic;
using Google.ProtocolBuffers.Descriptors;

namespace Google.ProtocolBuffers.ProtoGen
{
    public delegate TResult Func<T, TResult>(T arg);

    internal static class SourceGenerators
    {
        private static readonly Dictionary<Type, Func<IDescriptor, ISourceGenerator>> GeneratorFactories = new Dictionary
            <Type, Func<IDescriptor, ISourceGenerator>>
                                                                                                               {
                                                                                                                   {
                                                                                                                       typeof
                                                                                                                       (
                                                                                                                       FileDescriptor
                                                                                                                       )
                                                                                                                       ,
                                                                                                                       descriptor
                                                                                                                       =>
                                                                                                                       new UmbrellaClassGenerator
                                                                                                                           ((
                                                                                                                            FileDescriptor
                                                                                                                            )
                                                                                                                            descriptor)
                                                                                                                       },
                                                                                                                   {
                                                                                                                       typeof
                                                                                                                       (
                                                                                                                       EnumDescriptor
                                                                                                                       )
                                                                                                                       ,
                                                                                                                       descriptor
                                                                                                                       =>
                                                                                                                       new EnumGenerator
                                                                                                                           ((
                                                                                                                            EnumDescriptor
                                                                                                                            )
                                                                                                                            descriptor)
                                                                                                                       },
                                                                                                                   {
                                                                                                                       typeof
                                                                                                                       (
                                                                                                                       ServiceDescriptor
                                                                                                                       )
                                                                                                                       ,
                                                                                                                       descriptor
                                                                                                                       =>
                                                                                                                       new ServiceGenerator
                                                                                                                           ((
                                                                                                                            ServiceDescriptor
                                                                                                                            )
                                                                                                                            descriptor)
                                                                                                                       },
                                                                                                                   {
                                                                                                                       typeof
                                                                                                                       (
                                                                                                                       MessageDescriptor
                                                                                                                       )
                                                                                                                       ,
                                                                                                                       descriptor
                                                                                                                       =>
                                                                                                                       new MessageGenerator
                                                                                                                           ((
                                                                                                                            MessageDescriptor
                                                                                                                            )
                                                                                                                            descriptor)
                                                                                                                       },
                                                                                                                   // For other fields, we have IFieldSourceGenerators.
                                                                                                                   {
                                                                                                                       typeof
                                                                                                                       (
                                                                                                                       FieldDescriptor
                                                                                                                       )
                                                                                                                       ,
                                                                                                                       descriptor
                                                                                                                       =>
                                                                                                                       new ExtensionGenerator
                                                                                                                           ((
                                                                                                                            FieldDescriptor
                                                                                                                            )
                                                                                                                            descriptor)
                                                                                                                       }
                                                                                                               };

        public static IFieldSourceGenerator CreateFieldGenerator(FieldDescriptor field)
        {
            switch (field.MappedType)
            {
                case MappedType.Message:
                    return field.IsRepeated
                               ? (IFieldSourceGenerator) new RepeatedMessageFieldGenerator(field)
                               : new MessageFieldGenerator(field);
                case MappedType.Enum:
                    return field.IsRepeated
                               ? (IFieldSourceGenerator) new RepeatedEnumFieldGenerator(field)
                               : new EnumFieldGenerator(field);
                default:
                    return field.IsRepeated
                               ? (IFieldSourceGenerator) new RepeatedPrimitiveFieldGenerator(field)
                               : new PrimitiveFieldGenerator(field);
            }
        }

        public static ISourceGenerator CreateGenerator<T>(T descriptor) where T : IDescriptor
        {
            Func<IDescriptor, ISourceGenerator> factory;
            if (!GeneratorFactories.TryGetValue(typeof (T), out factory))
            {
                throw new ArgumentException("No generator registered for " + typeof (T).Name);
            }
            return factory(descriptor);
        }
    }
}